Currently memcg still use per node pgdat->lru_lock to guard its lruvec.
That causes some lru_lock contention in a high container density system.
If we can use per lruvec lock, that could relief much of the lru_lock
contention.
The later patches will replace the pgdat->lru_lock with lruvec->lru_lock
and show the performance benefit by benchmarks.
Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Wei Yang <richard.weiyang@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Arun KS <arunks@xxxxxxxxxxxxxx>
Cc: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: cgroups@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
include/linux/mmzone.h | 2 ++
mm/mmzone.c | 1 +
2 files changed, 3 insertions(+)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index bda20282746b..787a42d527a2 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -303,6 +303,8 @@ struct lruvec {
atomic_long_t inactive_age;
/* Refaults at the time of last reclaim cycle */
unsigned long refaults;
+ /* per lruvec lru_lock for memcg */
+ spinlock_t lru_lock;
#ifdef CONFIG_MEMCG
struct pglist_data *pgdat;
#endif
diff --git a/mm/mmzone.c b/mm/mmzone.c
index 4686fdc23bb9..3750a90ed4a0 100644
--- a/mm/mmzone.c
+++ b/mm/mmzone.c
@@ -91,6 +91,7 @@ void lruvec_init(struct lruvec *lruvec)
enum lru_list lru;
memset(lruvec, 0, sizeof(struct lruvec));
+ spin_lock_init(&lruvec->lru_lock);
for_each_lru(lru)
INIT_LIST_HEAD(&lruvec->lists[lru]);
--
1.8.3.1
